1. Field of the Invention
This invention relates to a refrigeration system equipped with an apparatus for detecting an insufficiency of refrigerant. This invention also relates to an apparatus for detecting insufficiency of refrigerant in a refrigeration system.
2. Description of the Prior Art
A automotive air conditioner refrigeration system have a known tendency to sometime allow refrigerant to leak out. The leakage of refrigerant finally results in an insufficiency of refrigerant. In refrigeration systems, insufficiency of refrigerant causes serious problems such as inadequate cooling cap abilities or in damage to compressors. There are various known devices for detecting an insufficiency of refrigerant in a refrigeration system.
Japanese published examined patent application No. 62-8704 discloses an apparatus for controlling the flow rate of refrigerant in refrigeration cycle. This apparatus includes a device for determining the degree of superheating of the refrigerant at the outlet of an evaporator. In general, superheating of refrigerant is caused by insufficiency of refrigerant. In the apparatus of Japanese patent application No. 62-8704, sensors detect temperatures of refrigerant at points upstream and downstream of the evaporator. The degree of superheating of refrigerant is determined in accordance with the detected temperatures of refrigerant at points upstream and downstream of the evaporator.
Devices disclosed in Japanese published unexamined utility model application No. 54-32137 and Japanese published examined patent application No. 57-38447 detect insufficiency of refrigerant in accordance with the pressure of refrigerant.